Abstract：
Flowering locus C (FLC) is a central transcriptional repressor that controls flowering time. However, how FLC is imported into the nucleus is unknown. Here, we report that Arabidopsis nucleoporins 62 (NUP62), NUP58, and NUP54 composed NUP62-subcomplex modulates FLC nuclear import during floral transition in an importin α-independent manner, via direct interaction. NUP62 recruits FLC to the cytoplasmic filaments and imports it into the nucleus through the NUP62-subcomplex composed central channel. Importin β supersensitive to ABA and drought 2 (SAD2), a carrier protein, is critical for FLC nuclear import and flower transition, which facilitates FLC import into the nucleus mainly through the NUP62-subcomplex. Proteomics, RNA-seq, and cell biological analyses indicate that the NUP62-subcomplex mainly mediates the nuclear import of cargos with unconventional nuclear localization sequences (NLSs), such as FLC. Our findings illustrate the mechanisms of the NUP62-subcomplex and SAD2 on FLC nuclear import process and floral transition, and provide insights into the role of NUP62-subcomplex and SAD2 in protein nucleocytoplasmic transport in plants.
摘要：
FLC是控制开花时间的中央转录抑制因子。然而,FLC是如何导入细胞核的还不清楚.这里,我们报道了拟南芥NUP62，NUP58和NUP54组成的NUP62亚复合物在花过渡期间以不依赖导入蛋白α的方式调节FLC核输入，通过直接互动。NUP62将FLC募集到细胞质细丝，并通过NUP62亚复合物组成的中央通道将其导入细胞核。进口蛋白βSAD2，一种载体蛋白，对FLC核进口和花卉过渡至关重要，这有助于FLC主要通过NUP62亚复合物导入细胞核。蛋白质组学,RNA-seq,和细胞生物学分析表明，NUP62-亚复合物主要介导具有非常规核定位序列（NLS）的货物的核进口，比如FLC。我们的发现说明了NUP62亚复合物和SAD2对FLC核导入过程和花过渡的机制，并提供有关NUP62亚复合物和SAD2在植物蛋白质核质运输中的作用的见解。本文受版权保护。保留所有权利。
